Send e-mail via Yahoo! Mail or Gmail by default

Normally, clicking on an e-mail address on a Web page will open up a new e-mail using your default e-mail program. If you'd rather use Yahoo! Mail, open up Options under Firefox's Tools menu, select the Applications tab, and scroll down to the mailto: entry. Select Use Yahoo! Mail and click OK.

Gmail is not included as a built-in option in every installation of Firefox, but if yours doesn't have it, you can add Gmail easily enough. Skip the Options dialogs for now and instead type about:config in Firefox's address bar and hit Enter. In the Filter field, type gecko.handlerServiceAllowRegisterFromDifferentHost. Actually, you can simply type gecko and find the entry in the filtered list. Double-click the gecko.handlerServiceAllowRegisterFromDifferentHost entry to change it to True.

Next, cut-and-paste this line into the address bar and hit Enter: javascript:window.navigator.registerProtocolHandler("mailto", "https://mail.google.com/mail/?extsrc=mailto&url=%s","Gmail")

A message will appear at the top of the browser window asking if you want to add Gmail as an application. Now, repeat the process above for choosing Yahoo! Mail, but select the new Use Gmail option instead.

Firefox addons

Here is the list of firefox addons that I like:

1. firebug - Useful if you want to see or edit code of a site on the go. (good tool for hacking interested people)
2. pdf download - Provides an option to download the pdf instead of opening it in the browser
3. flash block - doesn't load flash objects like advertisements. You get a play button, only when you click on that, that flash is loaded. Its better for people with low speed and low bandwidth.
4. google gears - allows you to use google reader and google docs even in the offline mode
5. download them all - its a great downloader addon, provides good features and speed

Other extension that I read but haven't tried is Greasemonkey. I read that it has many useful scripts that make life easier.